In order to investigate and diagnose orthopedic issues, X-ray images of a patient are often acquired which show a relatively long section of the patient's body, for example the vertebral column or a leg from the hip to the foot. Slot-scan radiography (SSR), for example, can be used for acquiring images of the type. In SSR, X-ray tube and X-ray detector are moved simultaneously along an axis of the patient while the X-ray beam is highly collimated into a slit. Owing to the strong collimation, i.e. because of the small aperture angle of the radiation field generated by the X-ray tube, the scattered radiation produced during the image acquisition is reduced, with the result that the patient is exposed to a smaller radiation dose compared to one or more composite standard radiographic images, while image quality is comparable.
A further scanning technique for acquisition of images of longer sections of the body is provided by parallel-scan tomosynthesis (PST). Compared with SSR, PST offers the advantage that a 3D tomosynthesis dataset can be generated by reconstruction, thereby enabling the overlapping of anatomical structures to be at least partially reduced. To that end, the collimator of an X-ray source is adjusted in such a way that a comparatively large aperture angle of the generated radiation field is produced. The image acquisition is then performed in such a way that as large an area of overlap as possible of the radiation field is obtained between the individual scans during an acquisition of a sequence of images. This enables 3D information to be generated during the scanning of anatomical features of the patient from different viewing directions. A method of such a type is described in U.S. Pat. No. 8,693,622 B2, for example.